title: Risk of surgery for subacromial impingement syndrome in relation to neck-shoulder complaints and occupational biomechanical exposures: a longitudinal study.
abstract: OBJECTIVE
  The aim of this longitudinal study was to evaluate the risk of surgery for subacromial impingement syndrome (SIS) in relation to neck-shoulder complaints and occupational biomechanical shoulder exposures.
  
  
  METHODS
  The study was based on the Musculoskeletal Research Database at the Danish Ramazzini Centre. We linked baseline questionnaire information from 1993-2004 on neck-shoulder complaints, job titles, psychosocial work factors, body mass index, and smoking with register information on first-time surgery for SIS from 1996-2008. Biomechanical exposure measures were obtained from a job exposure matrix based on expert judgment. We applied multivariable Cox regression.
  
  
  RESULTS
  During 280 125 person-years of follow-up among 37 402 persons, 557 first-time operations for SIS occurred. Crude surgery rates increased from 1.1 to 2.5 per 1000 person-years with increasing shoulder load. Using no neck-shoulder complaints and low shoulder load at baseline as a reference, no neck-shoulder complaints and high shoulder load showed an adjusted hazard ratio (HR(adj)) of 2.55 [95% confidence interval (95% CI) 1.59-4.09], while neck-shoulder complaints in combination with high shoulder load showed an HR(adj) of 4.52 (95% CI 2.87-7.13). Subanalyses based on 18 856 persons showed an HR(adj) of 5.40 (95% CI 2.88-10.11) for complaints located specifically in the shoulder in combination with high shoulder load.
  
  
  CONCLUSIONS
  Based on these findings, persons with neck-shoulder and especially shoulder complaints in combination with high shoulder load seem an obvious target group for interventions aimed at reducing exposures to prevent surgery for SIS.
authors.affiliation: Danish Ramazzini Centre, University Department of Occupational Medicine, Herning Regional Hospital, Gl. Landevej 61, DK-7400 Herning, Denmark. susasven@rm.dk.
authors.forename: Susanne Wulff
authors.initials: SW
authors.lastname: Svendsen
authors.forename: Annett
authors.initials: A
authors.lastname: Dalbøge
authors.forename: Johan Hviid
authors.initials: JH
authors.lastname: Andersen
authors.forename: Jane Frølund
authors.initials: JF
authors.lastname: Thomsen
authors.forename: Poul
authors.initials: P
authors.lastname: Frost
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003718:Denmark; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D012307:Risk Factors; D019534:Shoulder Impingement Syndrome / Q000503:physiopathology / Q000601:surgery*